1. Field of the Invention
The present invention relates to an automatic cutting and press-fitting apparatus which is used for cutting a covered electric wire for an automotive wire harness, peeling insulating covers of the so-cut wire at both ends thereof and press fitting both ends of the wire to terminals.
2. Description of the Related Art
As the automatic cutting and press-fitting apparatus of this kind, there is a press-fitting apparatus for press fitting both ends of the covered wire, disclosed in Japanese Patent Publication (kokai) No. 8-102354. FIG. 1 shows the press-fitting apparatus in the publication. The press-fitting apparatus 1 includes a loading station 3 where many wire supply tubes 3a are arranged on a base 2. The loading station 3 is adapted so as to move in the direction of arrow e. Provided on the wire-discharge side of the loading station 3 is a swivel arm 4 which has a not-shown clamp unit for clamping a wire W being supplied from the station 3. The swivel arm 4 is constructed so as to swivel or pivot right and left about a shaft 5 as the swivel center with respect to the base 2. The swivel arm 4 is also provided with a head part 4a which can occupy a base position H, a maximum rotational processing position J by a maximum pivot angle against the base position H and an intermediate processing position I between the position H and the position J, owing to the swivel operation of the swivel arm 4. The head part 4a opposes a wire cutting part 6A at the position H, a wire peeling part 6B at the position I and a terminal pressfitting part 6C at the position J, respectively.
As shown in FIGS. 1 and 2, the base 2 is provided, thereon, with a first transporting section 7 which is movable in both directions of arrows m and n. In the section 7, four (first to fourth) clamp parts 7a-7d are arranged at even intervals. The first clamp part 7a is moved between the base position H and a first processing position K, the second clamp part 7b between the first processing position K and a second processing position L, the third clamp part 7c between the second processing position L and a third processing position M, and the fourth clamp part 7d is moved between the third processing position M and a fourth processing position N, respectively.
The first clamp part 7a of the first transporting section 7 is arranged so as to oppose the wire cutting part 6A (FIGS. 1 and 3) by moving a movable cylinder 7S to the base position H along a cylinder rod 7R. The wire cutting part 6A includes a guide member 6a provided with an U-shaped groove for guiding the wire W, and a pair of cutting edges 6b, 6b for cutting the wire W, as shown in FIG. 3.
At the first processing position K of the first transporting section 7, a second transporting section 8 is arranged so as to move to a direction of arrow (p). The second transporting section 8 is provided with a clamp part 8a for clamping the wire W and adapted so as to transport it to a position opposing a peeling section 6D with the movement in the direction of arrow (p). At the second processing position L of the first transporting section 7, a third transporting section 9 is arranged so as to move to a direction of arrow (q). Having a clamp part 9a for clamping the wire W, the third transporting section 9 is also adapted so as to transport the wire W to a position opposing a terminal press-fitting section 6E with the movement in the direction of arrow (q).
At the third and fourth processing positions M, N of the first transporting section 7, there are provided a clamping section 6F and a wire discharging section 6G, respectively.
With the above-mentioned arrangement, the wire W is supplied from the supply station 3 to the swivel arm 4 and clamped by not-shown clamping means while the end portion of the wire W is projected from the head part 4a of the arm 4. Next, the projecting wire W is cut off by the wire cutting part 6A. After that, the swivel arm 4 is rotated from the reference position H to the intermediate position I. Successively, an insulating cover at one end of the so-cut wire W is peeled by the wire peeling part 6B and then, the swivel arm 4 is further rotated from the intermediate position I to a maximum rotational processing position J. At this position J, it is executed to press fit a terminal to a conductor of the wire W by the terminal press-fitting part 6C and thereafter, the arm 4 is returned from the position J to the reference position H. In this way, the processing for one end of the wire W is completed.
When the swivel arm 4 returns to the reference position H, then the first transporting section 7 is moved in the direction of arrow (m) so as to position the first clamp part 7a at the reference position H and the wire W of a predetermined length is drawn out through the head part 4a of the arm 4. Next, the so-drawn wire W is clamped by the first clamp part 7a of the first transporting section 7 and thereafter, the section 7 is moved in the direction of arrow (n) so as to position the part 7a at the first processing position K. After that, the second transporting section 8 does clamp the wire W over again through the clamp part 8a and sequentially moves in the direction of arrow (p), so that the wire W is moved in the vicinity of the wire peeling section 6D.
Next, it is carried out to peel the insulating cover on the other end of the wire W by wire peeling section 6D and thereafter, the second transporting section 8 returns to the initial position. Next, the second clamp part 7b of the first transporting section 7 is moved to the first processing position K to clamp the wire W over again. After clamping the wire W, the first transporting section 7 is shifted to the direction of arrow (n), so that the second clamp part 7b occupies in the second processing position L. After that, the third transporting section 9 does clamp the wire W through the clamp part 9a over again and sequentially moves in the direction of arrow (q), so that the wire W is moved in the vicinity of the terminal press-fitting section 6E.
At the terminal press-fitting section 6E, it is executed to press fit the terminal to the conductor at the other end of the wire W and thereafter, the third transporting section 9 returns to the initial position. Next, the third clamp part 7c of the first transporting section 7 is moved to the second processing position L to clamp the wire W over again. After clamping the wire W, the first transporting section 7 is shifted to the direction of arrow (n), so that the third clamp part 7c occupies in the third processing position M. Next, the wire W is clamped by the clamping section 6F over again and successively moved to the fourth processing position N with the movement of the first transporting section 7, for discharging the wire W through the wire discharging section 6G. In this way, the processing of the other end of the wire W is completed, too.
The above-mentioned press-fitting apparatus 1 has the following drawbacks.
First, on the way of the head 4a of the arm 4 from the position J to the reference position H, there is sometimes caused a problem that the insulating cover of the wire W, the terminal fixed thereto, etc. are damaged to produce inferior products because the leading portion of the wire W is bent and caught on cutting edges 6b (FIG. 3) of the wire cutting part 6A, or the like, under the influence of weight of the terminal being press-fitted on the end of the wire W, etc.
Second, when drawing the wire W out of the head part 4a of the arm 4 in order to clamp the wire W on the first clamp part 7a of the first transporting section 7, there is also caused a problem of inaccurate pinching of the wire W by the first clamp part 7a since the leading portion of the wire W is bent to interfere with a lower plate 7P (FIG. 2) of the first transporting section 7, due to the weight of the terminal.